Calculators / General

Everyday Math, Simplified

19 general-purpose calculators for age, percentage, fractions, ratios, statistics, and everyday math problems.

19 free tools No sign-up · Instant results · 100% free

All General Calculators (19 tools)

Age Calculator

Calculate your exact age in years, months, weeks, days, hours and minutes.

Percentage Calculator

Calculate percentages, increases, decreases, and percentage differences.

Discount Calculator

Calculate discount amount, sale price, and savings from any percentage off.

Tip Calculator

Calculate tip amount, total bill, and per-person split for any group size.

Age Difference Calculator

Calculate the exact age difference between two people in years, months, and days.

Average Calculator

Calculate mean, median, mode, weighted average, and standard deviation.

Fraction Calculator

Add, subtract, multiply, divide fractions. Simplify and convert to decimals.

Ratio Calculator

Simplify ratios, scale ratios, find equivalents, and convert to percentages.

Roman Numeral Converter

Convert numbers to Roman numerals and back. Date and year converter.

Random Number Generator

Generate cryptographically secure random numbers, lottery picks, dice rolls.

Scientific Calculator

Full scientific calculator with trig, logs, powers, factorial, and memory.

Probability Calculator

Calculate basic probability, combined events, binomial, and Bayes theorem.

LCM & HCF Calculator

Find LCM and HCF/GCD of up to 6 numbers with step-by-step methods.

Number Base Converter

Convert between binary, decimal, octal, hex, and any base (2-36).

Loan vs Buy Calculator

Compare buying cash vs taking a loan with true cost analysis.

Dice Roller

Roll any combination of dice — d4, d6, d8, d10, d12, d20, d100 — with true randomness.

Standard Deviation Calculator

Calculate standard deviation, variance, and full statistics with step-by-step.

Electricity Bill Calculator

Calculate your electricity bill based on appliance usage and your unit rate.

Days Until Calculator

Calculate how many days until any future date or event.

Explore Other Categories

Discover more free tools across all our calculator categories.

Finance 48 tools Health 24 tools Education 12 tools Conversion 12 tools Utility 26 tools Math & Stats 12 tools Technology 7 tools

Frequently Asked Questions

How do I calculate percentage?

Percentage = (Part / Whole) × 100. Our Percentage Calculator also handles reverse calculations like "X is what % of Y?" and "find the original value before a percentage change."

How is age calculated exactly?

Age is calculated from your date of birth to the current date in years, months, and days. Our Age Calculator also shows your age in weeks, days, hours, and minutes.

What is standard deviation?

Standard deviation measures how spread out numbers are in a dataset. A low SD means values cluster close to the mean; a high SD means they are spread out. Use our Standard Deviation Calculator for instant results.

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